New Insight on the Study of the Kinetic of Biobased Polyurethanes Synthesis Based on Oleo-Chemistry

Development of lactic acid based chain extender and soybean oil-derived polyurethanes for ecofriendly sustained drug delivery systems

In the present study, a range of sustainable, biocompatible and biodegradable polyurethanes (PU-1 to PU-4) were synthesized using different combinations of biobased polyol (obtained through the epoxidation of soybean oil, followed by ring opening with ethanol) and polyethylene glycol (PEG) and isophorone diisocyanate. The sustainable chain extender used in this study was synthesized by the esterification of lactic acid with ethylene glycol (EG). The synthesized PU samples were characterized through scanning electron microscopy (SEM), Fourier transformed infrared (FTIR) and nuclear magnetic resonance (1H NMR and 13C NMR) spectroscopy. Wetting ability and thermal degradation analysis (TGA) of the samples were also studied. Subsequently, these PUs were examined as potential drug delivery systems using Gabapentin as a model drug, which was loaded in the polymer matrix using the solvent evaporation method. The drug release studies were carried out in 0.06 N HCl as a release medium according to the method outlined in the United States Pharmacopeia. The maximum drug release was observed for sample PU-P1, which was found to be 53.0 % after 6 h. Moreover, a comparison of different PU samples revealed a trend wherein the values of drug release were decreased with an increase in the PEG content.

Paving the Way towards Sustainability of Polyurethanes: Synthesis and Properties of Terpene-Based Diisocyanate

Due to growing concerns about environmental issues and the decline of petroleum-based resources, the synthesis of new biobased compounds for the polymer industry has become a prominent and timely topic. P-menthane-1,8-diamine (PMDA) is a readily available compound synthesized from turpentine, a cheap mixture of natural compounds isolated from pine trees. PMDA has been extensively used for its biological activities, but it can also serve as a source of valuable monomers for the polymer industry. In this work, commercial PMDA (ca. 85% pure) was purified by salinization, crystallization, and alkali treatment and then converted into p-menthane-1,8-diisocyanate (PMDI) through a phosgene-free synthesis at room temperature. A thorough analytical study using NMR techniques (1H, 13C, 13C-1H HSQC, 13C-1H HMBC, and 1H-1H NOESY) enables the characterization of the cis-trans isomeric mixtures of both PMDA and PMDI. These structural studies allowed for a better understanding of the spatial configuration of both isomers. Then, the reactivity of PMDI with a primary alcohol (benzyl alcohol) was studied in the presence of nine different catalysts exhibiting different activation modes. Finally, the use of PMDI in the synthesis of polyurethanes was explored to demonstrate that PMDI can be employed as a new biobased alternative to petrochemical-based isocyanates such as isophorone diisocyanate (IPDI).

Oxazolidone formation: myth or fact? The case of biobased polyurethane foams from different epoxidized triglycerides

Study of the oxazolidone formation by reaction between disubstituted epoxide and isocyanate in polyurethane foams and model.